Pneumatic safety starting and shutdown system for internal combustion engines



Aug. 9, 1955 M Q METZGER 2,714,883

PNEUMATIC SAFETY STARTING AND SHUTDOWN SYSTEM FOR INTERNAL COMBUSTION ENGINES Filed Oct. 17. 1950 l 6 Sheets-Sheet l Nm @z usnmm Om mmnmmmmm INVENTOR.

MARTIN C. METZGER Aug. 9, 1955 M. c. METZGER PNEUMATIC SAFETY STARTING AND SHUTDOWN SYSTEM FOR INTERNAL COMBUSTION ENGINES Filed OGC. 17, 1950 6 Sheets-Sheet 2 INVENTOR.

MARTI N C. METZGER Aug. 9, 1955 M. c. METzGl-:R 2,714,883

PNEUMATIC SAFETY STARTING AND SHUTDOWN SYSTEM FOR INTERNAL COMBUSTION ENGINES Filed Oct. 17. 1950 6 Sheets-Sheet 3 RESERVOIR NEEDLE VALVE TIME DELAY U'ACKET WATER TEMP. VALVE LUBE olL. PRESSURE VALVE ENG-INE OVERSFEED VALVE OIL FUEL. CONTROL VALVE FIG.4

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GAS FUEL CONTROL VALVE Aug. 9, 1955 M C, METZGER 2,714,883

PNEUMATIC SARETY STARTING AND SHUTDOWN SYSTEM FOR INTERNAL COMBUSTION ENGINES Filed Oct. 17, 1950 6 Sheets-Sheet 4 MARTIN (LMETZGER INVENTOR.

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Aug. 9, 1955 M. c. METZGER 2,714,883

PNEUMATIC SAFETY STARTING AND SHUTDOWN SYSTEM FOR INTERNAL COMBUSTION ENGINES 6 Sheets-Sheet 5 Filed OGt, 17, 1950 INVENTOR.

MARTIN C. M ETZGER AIR PRESSURE Aug. 9, 1955 M Q METZGER 2,714,883

PNEUMATIC SAETY STARTING AND SHUTDOWN SYSTEM FOR INTERNAL COMBUSTION ENGINES Filed Oct. 17. 1950 6 Sheets-Sheet 6 FIG-7 MARTIN C.METZGER INVENTOR.

United States Patent O PNEUMATIC SAFETY STARTING AND SHUT- DWN SYSTEM FOR INTERNAL `COMBUS- TIQN ENGINES Martin C. Metzger, Buffalo, N. Y., assignor to Worthington Corporation, a corporation of Delaware Application October 17, 1950, Serial No. 190,573 12 Claims. (Cl. 12S- 198) This invention relates to a pneumatic safety and shutdown system for diesel, gas and dual fuel internal combustion engines. An object of the present invention is to provide means for shutting down an internal combustion engine of the type using oil, gas, or a combination of oil and gas, as fuel, upon failure of `any one of various parts of the engine unit such as adrop in lubricating oil `pressure below the safe limits of operation, an increase in jacket water temperature above safe limits of operation, an increase in engine speed above the safe limits of operation, failure of supply air below `the required pressure, etc., and primarily to shut down the engine by cutting oli the supply of fuel thereto without affecting the ignition system of the engine, and to provide means whereby the engine cylinders will be thoroughly scavenged of residual gases upon restarting of the engine, thus avoiding undesirable and often serious explosions in the scavenge or exhaust system.

Primarily, the present invention consists of means for:

(n) Automatically shutting off the fuel gas whenever the engine is shut down for any reason;

(b) Leaving the ignition on so that any residual gas in the engine when it is shut down can be burned, and

(c) Automatically making it necessary to turn the engine over a predetermined number of revolutions on starting air before the fuel supply to the engine is automatically turned on so as to purge the engine before the -delivery of fuel thereto.

With these and other objects in view, as may appear from the accompanying specification, the invention consists of various features of construction and combination of parts, which will be first described in connection with the accompanying drawings, showing a pneumatic safety starting and shutdown system for internal combustion engines of a preferred form embodying the invention, and

the features forming the invention will be specifically pointed out in the claims.

In the drawings:

Figure l is a diagrammatic view showing the pneumatic safety starting and shutdown system applied to a gas fuel internal combustion engine.

Figure 2 is a fragmentary diagrammatic view showing the pneumatic safety starting and shutdown system applied to an oil, fuel or diesel type internal combustion engine.

Figure 3 is a detail view of a part of the mechanism employed in the system when used on a diesel or oil fuel engine.

Figure 4 is a fragmentary diagrammatic view showing the pneumatic safety starting and shutdown system applied to a dual fuel internal combustion engine.

Figure 5 is a vertical section through one form of fuel control valve employed in the system.

Figure 6 is a side elevation partly in section of one form of air control valve employed in the system.

Figure 7 is a vertical section through one form of jacket water temperature control valve employed in the system.

ZJLSS Patented Aug. 9, 1955 Figure 8 is a vertical section through one form of lubrieating oil pressure control valve employed in the system.

Figure 9 is a detail view partly in section of the engine speed controlled and operated valve mechanism employed in the system.

Referring more particularly to the drawings, Figure l shows the pneumatic safety starting and shutdown system associated with a gas fuel internal combustion engine including a cylinder 1, piston 2, the usual type of governor operated fuel inlet valve 3, spark ignition 4, cooling water jacket 5 and exhaust valves and system 6. The internal combustion engine is equipped with the usual type of pressure air starting system (not shown) but which is well known in the art, and pressure air for the starting system is supplied from any suitable source of air under pressure through the supply pipe 10. A manually operated valve 11 is placed in the pipe Ill to permit manual control of the delivery of starting air pressure to the system. A pressure actuated piston valve structure 12 is connected in the pipe 10 between the manually operable valve 11 and the engine starting system (not shown) and this valve structure which is shown in Figure 6 of the drawings includes any approved type of vertically movable valve head (not shown) which seats upon the usual type of seat (not shown) enclosed in the housing 13 for control* ling the llow of air through the pipe 10. The stem 14 of the valve (not shown) projects out of the housing 13 and 1s positioned for engagement by a pressure actuated piston 15 which is moved into its upper or non-Valve operating position by a spring 16 and is moved downwardly .to open the valve 12 by air pressure delivered to the cylinder 13 through the branch sure air is delivered to the cylinder 13 the piston 15 is forced downwardly against the tension of the spring 16 tolmove the valve stem i4 downwardly and unseat the va ve.

plunger' 22. The plunger 22 when in 1n Figure 6 of the drawings permits pressure air through the valve seat 23 through the valve seat 26 to the vent 27, thus venting the an' pressure from the line beyond the valve 18.

If it is desired, a strainer 28 may be positioned in the by-pass or branch pipe l? between the pipe 1t) and englne starting valve 18.

through a second or branch pipe 36 to a lubricating oil pressure actuated valve 37.

One form of jacket water temperature operated valve structure 35 is shown in section in Figure 7 of the drawings, and while this particular type of valve is shown in the drawings and described herein, it is to be understood that any other suitable type of temperature actuated valve mechanism may be employed in the system.

The temperature operated valve structure 35 illustrated in Figure 7 includes valve housing 38 in which is mounted a reciprocatory Valve element 39 for controlling the flow of pressure air through the valve structure. The reciprocatory valve element 39 is actuated through suitable mechanism by variations in temperature of the cooling water in the cooling jacket of the engine through the medium of a thermal bulb 48. The thermal bulb 40 and the mechanism operated thereby, as well as the valve structure are all of a well known type which may be purchased upon the open market, and the specific construction thereof forms no part of the present invention.

The lubricating oil pressure actuated valve 37 is likewise a well known type of valve and may be purchased upon the open market, and one form of such valve and its operating mechanism is shown in Figure 8 of the drawings wherein the valve housing 41 contains a reciprocable valve element 42 cooperating with the valve seat 43 to control the llow of air pressure therethrough. The reciprocating valve element 42 is operated through suitable pressure actuated elements 44 by the pressure of the lubricating oil used in the internal combustion engine and lubricating oil from the lubricating system of the engine is delivered to the valve 37 through the pipe 45. It will be noted by reference to Figures 7 and 8 of the drawings that both the valves 37 and 35 have three ports: namely, two inlet ports, 46, 46 and 47, 47 and an outlet port 48, 48 as indicated on the respective valves.

Valves 35 and 37 are also indicated in Figures 7 and 8, normally disposed to provide communication between their respective, ports 47 and 48 and 47 and 48. In this position, no communication is provided between ports 47 and 48 with port 46 of valve 37 or between ports 47 and 48 with port 46' of valve 35. Conversely, when valve element 39 or 42 on the respective valves 35 and 37 are actuated by excessive temperature or change in oil pressure as above described, communication between ports 47 and 48 and 47 and 48 of the respective valves 37 and 35 is closed, and communication between ports 48 and 46 and 48 and 46' of these same respective valves 37 and 35 opened, for the purposes and functions as set forth hereinafter in the statement of operation of the present invention.

A pipe 49 is connected to the pipe 10 outwardly of the manually operated valve 11 and to the inlet port 46 of the valve 37 to supply air under pressure to the port 46 at all times when the manually operated valve 50 is open. A pressure reducing valve 51 is placed in the pipe 49 between the valve 50 and the inlet port 46 and if it is so desired, a strainer 52 may be interposed in this air line between the pressure rducing valve 51 and the valve 50.

A pipe 53 connects the outlet port 48 of the valve 37 to the inlet port 47 of the valve 35. The pipe 36 from the reservoir 33 is connected to the inlet port 47 of the valve 37 and the outlet pipe 34 from the reservoir 33 is connected to the inlet port 46 of the valve 35. The outlet port 48 of the valve 35 is connected to an engine overspeed valve 54. The engine overspeed valve 54 is of the same construction as the engine starting valve 18 including a plunger 55 which controls the passage of pressure air through the valve structure 54 either to permit the pressure air to ow through the valve 54 into the pipe 56 or to vent from the pipe 56 to atmosphere depending upon the position of the plunger 55. The

plunger is operated from the flywheel 57 of the engine through the medium of a contact arm 58 and articulated pivoted lever structures 59 through the medium of a spring pressed pin 60 which is carried by the flywheel and is normally held in retracted position by means of a spring 61. However, when the speed of operation of the engine and, consequently, the speed of rotation of the flywheel 57 exceeds a predetermined safe operating speed for the engine the centrifugal force will cause the plunger headed pin 60 to protrude from the perimeter of the flywheel 57 so that it will engage the contact arm 58 and operate the valve 54 in the manner hereinafter described.

The pipe 56 is connected to the engine fuel control valve 65. The engine fuel control valve is connected in the fuel supply pipe 66 which delivers fuel to the engine cylinder 1.

One form of the pressure actuated fuel control valve is shown in section in Figure 5 of the drawings and this construction of valve is one that is well known and may be purchased upon the open market. It is understood that any other suitable type of pressure actuated fuel control valve which may be purchased upon the open market may be substituted for that shown in Figure 5. The figure being provided by way of showing one form of suitable valve.

' The engine fuel control valve structure 65 includes the valve housing 67 having the reciprocable valve element 68 mounted therein which cooperates with the valve seats 69 to control the delivery of fuel to the engine cylinder 1. The stem 70 of the reciprocable valve element 68 is connected to a diaphragm 71 attached to a pressure expansible bellows or element 72. The pressure air through the pipe 56 is delivered into the expansible element or against the diaphragm 71 so as to move the valve element 68 downwardly to open the valve to permit delivery of fuel to the engine. When the pressure against the diaphragm or in the expansible element 72 is relieved the spring 73 will seat the valve element 68 on the valve seat 69 and cut off the ilow of fuel to the engine.

Operation In starting the engine, the operation is as follows:

First, manually operated valves 11 and 50 are opened to pass pressure air from main line 10 simultaneously to lines 17 and 49 connected thereto. f

Line 17 passes the air through strainer 28 to the engine starting valve 18 and line 49 passes the air through strainer 52 and pressure reducing valve 51 to the port 46 of the lubricating oil pressure actuated valve 37.

Since valve 37 will have its ports 47 and 48 in communication with each other when the lubricating oil pressure has not reached the predetermined safe operating pressure as would be the case during starting up, shutdown emergency, or the like conditions of operation of the engine, no pressure air passes from port 46 to port 48 in the valve 37 as is clearly shown in Figure 8 of the drawings.

When plunger 24 of the air starting valve 18 is now moved to an open position as shown in Figure 6 of the drawings, pressure air flows through lines 17 to the reservoir 33 and through line 29 connected to line 17 to the cylinder 13 of the valve 13.

Pressure air delivered to cylinder 13 of valve 13 actuates the piston 15 therein to open valve 13 thereby permitting pressure air in line 10 to be delivered to the starting system (not shown) of the engine, which starting air is used to turn the engine over for a suiicien't length of time to insure complete purging of combustible gases from the engine and its manifolds.

Line 17 is further provided with a pressure reducing valve 31 and a time delay needle valve 32 between the point where the line 29 connects thereto and the reservoir 33. The time delay needle valve 32 is manually operated valve employed to regulate the ow of air to the reservoir 33, thus providing an adjustable control of the time required for the air pressure to build up in the starting system and to further control the time allowed to purge the engine and its manifold system of all combustible gases before starting the engine.

After the engine is purged of combustible gases the ignition system (not shown) thereof is placed in operation and the fuel throttle (also not shown) may then be moved gradually from a stop to a run position as is customary in the starting up of these engines.

However, the fuel to the engine must be delivered through line 66 having the fuel control valve 65 therein. Therefore, the fuel control valve 65 must be actuated by pressure air to an open position as above described.

This is accomplished initially by the pressure air which is delivered from the reservoir 33. Thus, line 34 passes pressure air to connecting conduit 36 connected between line 34 and port 47 of the lubricating oil pressure actuated Valve 37. Since this valve, during starting up, will have the ports 47 and 48 in communication with each other, this pressure air will pass through ports 47 and 48 to line 53 connected to port 47 of the jacket water temperature actuated valve 35. Since the temperature at starting up is generally never excessive, valve 35 will have its ports 47 and 48 in communication with each other and, accordingly, the air at receiver pressure will pass from port 47 through the valve to port 48 whence it is led by the line 56 connected to the port 48 to the pressure actuating elements 71 of the engine fuel control valve 65 actuating the valve 65 to an open position to allow fuel to pass through the line 66 to the engine.

An engine overspeed valve, generally designated 54, has been provided in the line 56 but this valve is normally open until such time as the engine tends to overspeed, at which time it is actuated to a closed position as has been heretofore described.

When the engine starts with delivery of fuel thereto, the pressure of the oil in the lubricating system of the engine delivered to the pressure element of the lubricating oil pressure actuated valve 37 through line 45 increases above the minimium required for safe engine operating pressure, and causes the pressure actuating element 44 to change the position of the valve 42 thereby cutting olf communication between ports 47 and 48 and opening communication between ports 46 and 48 of this valve. The pressure air in line 49 is now delivered through port 46 to port 48 of the valve 37 and thence through line 53 connected to the port 48 to port 47' of the jacket water temperature actuated valve 35. Since the jacket water temperature wiil still not be excessive, the pressure air continues through valve 35 and line 56 tothe pressure actuated element 71 of the engine control valve 65 as above described, and fuel will continue to be delivered through line 66 to the engine without any break in the continuity of operation between the manual starting up and the automatic shut-down control system.

The plunger 24 of the engine starter valve 18 is now returned manually to its shut-off position to prevent flow of pressure air to the cylinder 13 and to vent to atmosphere simultaneously air in line 29 and line 17 communicating with the reservoir 33, through the vent 27 provided in the valve 18. Air from the reservoir bleeds back through the by-pass `or branch pipe 75 disposed between line 17 and line 29. A check valve 76 is provided in this line to prevent air at main line pressure from passing from the line 29 to the reservoir 33 during the starting up operation.

It is believed clear that the automatic shut-down operation of this system comes into being as soon as the pressure in the lubrication system for the engine is above the predetermined safe operating limit. If the pressure of the lubricating oil falls below the predetermined minimium safe operating limit, the pressure actuating element 44 will cause the valve 42 to change its position once again whereby communication between ports 48 and 46 is cut off and communication between 46 and 47 is open. This will cause pressure air to stop flowing through the valve 37 and expand and bleed the air in line 53, valve 35, and line 56 through port 48; port 47 now in communication therewith, line 36 and line 34 to the reservoir 33. The reservoir in turn is vented through line 75 and line 17 through the valve 18 to atmosphere as above described. Spring element 73 will actuate the valve 65 to its closed position, thereby cutting olf the flow of fuel to the engine through line 66.

Similarly, in the event that the temperature of the cooling water in the cooling jacket 5 of the engine reaches an excessive temperature, the valve 39 of the jacket water temperature actuated valve 35 will be caused to change its position so that port 48 no longer communicates with 47 but does communicate with port 46. This prevents pressure air from line 53 "passing through Valve 35 to line 56 and acts to expand or bleed the air from line 56 through ports 48 and 46 in communication with each other to the line 34 connected to port 46 into the reservoir 33. The reservoir is in turn vented to atmosphere as above described. Reduction in air pressure in line 56 will in turn permit spring 73 to deactuate the pressure actuating element 71 of the engine fuel control valve 65 and thus cause this valve to close, thereby cutting olf delivery of fuel to the engine.

If the engine overspeeds, the plunger 55 of the overspeed valve 54 will vent line 56 to atmosphere which will also cause deactuation of the pressure actuating element 71 of the valve 65 thereby allowing the spring element 73 to close the valve and to prevent delivery of fuel through line 66 to the engine.

The reservoir 33 is provided in the system to add air holding volume to the system during the starting operation and it acts as an air expansion chamber when the valve 35 or valve 37 operate to shut down the engine, and ultimately venting to atmosphere as above described.

Figures 2 and 3 of the drawings show the improved pneumatic safety starting and shutdown system as applied to an oil fuel engine, that is, to a diesel engine, and in this construction, as is usual in the construction of such engines oil fuel is supplied to the engine (not shown) by the usual type of oil fuel pump and to permit adaption of the automatic safety starting and shutdown system to the diesel engine the rack or racks 101 of the oil fuel pumps are connected to a bell crank 102. One end of the bell crank 102 engages the perimeter of a cam 103 which is carried by a shaft 104. A weighted wheel 105 is mounted on the shaft 104 for rotating the shaft to rotate the cam 103 to operate the bell crank 102 which in turn operates the rack 101 of the fuel pump 100 and cuts off the delivery of fuel oil to the engine.

During normal operation, however, the weighted wheel 104 is held in engine operating position by means of a holding arm 106. This holding arm may be in the form of a pivoted arm as shown in Figure 3 of the drawings, having a lug 107 at one end thereof which engages in a notch 108 in the perimeter of the wheel 105. The arm 106 is connected to a rod or stem 109 and the stern 109 is connected to a pressure actuated element of an air pressure actuated structure 110. The structure is identical with the fuel oil control valve 65 hereto described excepting only that the stem 109 which corresponds to the stem 70 is connected to the arm 106 instead of to the reciprocator valve element 68. Air pressure is supplied to the device 110 through the pipe 111 which corresponds to the pipe 56. Delivery of air under pressure to the pipe 111 is under control of the various valves and elements of the system, as described in connection with Figure l of the drawings, :and in Figure 2 of the drawings the engines overspeed valve structure 54 and its operating mechanism is shown, it being understood that the various other valves and the reservoir are connected to the pipe 112 in the same manner as shown in Figure l of the drawings.

In Figure 4 of the drawings, the improved pneumatic safety starting and shutdown system for internal combustion engines is illustrated as adaptable to or applied to a dual fuel engine, that is, an engine which operates on a combination of oil and gas or on either, being ignited by a pilot delivery of oil.

In adapting the system to a dual fuel engine, a gas fuel control valve 120, which is identical in construction with the valve 65, is connected by a branch pipe 121 to the pipe 122 which corresponds to the pipe 56, and an oil fuel control valve 123 which is identical in construction to the valve 65, is connected by a branch pipe 124 to the pipe 122. The pipe 122 is connected to an engine overspeed valve 125, a jacket water temperature actuated valve 126, a lubricating oil pressure actuated valve 127, all of which are identical to the corresponding elements shown in Figure l and described in connection therewith. The reservoir 128 and the time delay needle valve 129 shown in Figure 4 of the drawings are identical with the reservoir 33 and the needle valve 32, and all of these elements operate in identically the same manner as described in connection with the operation of Figure 1 and control the delivery of gas fuel or oil fuel to the engine to delay the starting of the engine or to stop the engine in the manner described in connection with Figure 1,

In the following claims, the jacket water temperature valve and/ or lubricating oil pressure operated valves of the system are generically referred to as stop valves, and the starting air pressure actuated control valve 12 is generically referred to as a piston valve for the purpose of identifying various valves and simplifying the language of the claims.

It will be understood that the invention is not to be limited to the specific construction or arrangement of parts shown, but that they may be widely modified within the invention defined by the claims.

What is claimed is:

l. In a pneumatic safety starting and shutdown system for internal combustion engines, the combination with an internal combustion engine embodying a pressure air operated starting system and a conduit for delivering pressure air to said starting system, of a pressure air actuated valve controlling delivery of fuel to the engine, a manually operated valve in said starting air conduit, a first pipe connected to said conduit downstream of said manually operable valve and connected to said fuel control valve to deliver operating pressure air to the fuel control valve, a manually operable starting valve interposed in said first pipe and operable to admit flow of pressure air to the fuel control valve or to bleed pressure air from the line leading to the fuel control valve, a second pipe connected to said conduit upstream of said manually operable valve and connected to said fuel control valve for delivering air pressure thereto independently of said starting valve, and a valve interposed in said first and second pipe connections to said fuel control valve and operable when said starting valve is opened to admit passage of air from said first pipe 'to said fuel control valve and cut off pressure of air to the fuel control valve from said second pipe, said valve operable when said starting valve is in bleedoff position to admit pressure air from said second pipe to said fuel control valve.

2. A pneumatic safety starting and shutdown system for internal combustion engines as claimed in claim l wherein the valve interposed in said first and second pipes is operable under predetermined abnormal operating conditions of the engine to cut off all flow of pressure air to said fuel control valve.

3. A pneumatic safety starting and shutdown system for internal combustion engines as claimed in claim 1 wherein a pressure actuated valve is interposed in said conduit downstream of the connection of said first pipe and saidconduit, a branch pipe connecting said first pipe and said pressure actuated valve downstream of said starting valve 'to supply operating pressure air to the pressure actuated valve when the starting valve is in pressure air admitting position to open the pressure actuated valve, and to bleed pressure air from the pressure actuated valve when the starting valve is in bleedoff position to close the pressure actuated valve and cut off supply of pressure air to the engine starting system.

4. A pneumatic safety starting and shutdown system for internal combustion engines as claimed in claim 1 wherein the valve interposed in said first and second pipes is operable under predetermined abnormal operating conditions of the engine to cut off all flow of pressure air to said fuel control valve, a pressure actuated valve interposed in said conduit downstream of the connection of said first pipe and said conduit, a branch pipe connecting said first pipe and said pressure actuated valve downstream of said starting valve to supply operating pressure air to the pressure actuated valve when the starting valve is in pressure air admitting position to open the pressure actuated valve, and to bleed pressure air from the pressure actuated valve when the starting valve is in bleedoff position to close the pressure actuated valve and cut off supply of pressure air to the engine starting system.

5. A pneumatic safety starting and shutdown system for internal combustion engines as claimed in claim 1 including a pressure air reservoir connected to said first pipe to provide pressure air holding volume to the safety starting and shutdown system when said starting valve is in pressure air admitting position.

6. A pneumatic safety starting and shutdown system for internal combustion engines as claimed in claim 1 wherein the valve interposed in said first and second pipes is operable under predetermined abnormal operating conditions of the engine to cut off all fiow of pressure air to said fuel control valve, a pressure air reservoir connected in said first pipe to provide pressure air holding volume to the safety starting and shutdown system when said starting valve is in pressure air admitting position, said reservoir also connected to said pressure operated valve through said first pipe and operative to provide an air expansion chamber when said stop valve is operable under predetermined abnormal operating conditions of the engine to cut off all flow of pressure air to the fuel control valve.

7. A pneumatic safety starting and shutdown system for internal combustion engines as claimed in claim 1 wherein the valve interposed in said first and second pipes is operable under predetermined abnormal operating conditions of the engine to cut off all ow of pressure air to said fuel control valve, a pressure actuated valve interposed in said conduit downstream of the connection of said first pipe and said conduit, a branch pipe connecting said first pipe and said pressure actuated valve downstream of said starting valve to supply operating pressure air to the pressure actuated valve when the starting valve is in pressure air admitting position to open the pressure actuated valve, and to bleed pressure air from the pressure actuated valve when the starting valve is in bleedoff position to close the pressure actuated valve and cut off supply of pressure air to the engine starting system.

8. A penumatic safety starting and shutdown system for internal combustion engines as claimed in claim l wherein the valve interposed in said first and second pipes is connected to the lubricating system of the engine and is operable upon failure of lubricating oil pressure to cut off all fiow of pressure air to said fuel control valve.

9. A pneumatic safety starting and shutdown system for internal combustion engines as claimed in claim l wherein the valve interposed in said first and second pipes is connected to the lubricating system of the engine and is operable upon failure of lubricating oil pressure to cut off all flow of pressure air to said fuel control valve, a -CQuCl Valve interposed between said first valve and said fuel control valve, and means acted upon by the temperature of the engine cooling water for operating said second valve whereby when the temperature of the cooling water rises above a predetermined degree said second valve will be operated to cut o ilow of pressure air to said fuel supply control valve independently of operation of said first stop valve.

l0. A pneumatic safety starting and shutdown system for internal combustion engines as claimed in claim 9 wherein the engine includes a llywheel, an engine overspeed valve interposed in the pipe between said second stop valve and said fuel supply control valve, said overspeed valve including a plunger, means for moving said plunger to bleed pressure air from said fuel supply control valve, and normally retracted means carried by said flywheel and movable when the speed of rotation of the flywheel exceeds a predetermined speed to move said plunger into pressure air bleeding position to cut off supply of pressure air to said fuel control supply valve independently of said stop valves.

11. A pneumatic safety starting and shutdown system for internal combustion engines as claimed in claim 1 wherein the engine includes a flywheel, an engine overspeed valve interposed in the pipe between said second stop Valve and said fuel supply control Valve, said overspeed valve including a plunger, means for moving said plunger to bleed pressure air from said fuel supply control valve, and normally retracted means carried by said flywheel and movable when the speed of rotation of the flywheel exceeds a predetermined speed to move said plunger into pressure air bleeding position to cut off supply of pressure air to said fuel control supply valve independently of said stop valves.

l2. In a pneumatic safety starting and shutdown system for internal combustion engines, the combination with an internal combustion engine embodying a pressure air operated starting system and a conduit for delivering pressure air to said starting system, of a pressure air actuated valve controlling delivery of fuel to the engine, a manually operated valve in said starting air conduit, a rst pipe connected to said conduit downstream of said manually operable valve and connected to said fuel control valve to deliver operating pressure air to the fuel control valve, a manually operable starting Valve interposed in said first pipe and operable to admit llow of pressure air to the fuel control valve or to bleed pressure air from the line leading to the fuel control valve, a second pipe connected to said conduit upstream of said manually operable valve and connected to said fuel control Valve for delivering air pressure thereto independently of said starting valve, and a plurality of valves arranged in sequence and interposed in said first and second pipe connections to said fuel control valve, said valves operable under normal operating conditions of the engine to control operation of said engine fuel control valve to permit delivery of fuel to the engine and independently operable under predetermined abnormal operating conditions of the engine to operate the engine fuel control valve to cut off the supply of fuel to the engine.

References Cited in the lile of this patent UNITED STATES PATENTS 1,473,303 Lightford Nov. 6, 1923 2,010,960 Pogue Aug. 13, 1935 2,395,202 Stevens et al Feb. 19, 1946 2,423,728 Ray July 8, 1947 2,435,343 Downey Feb, 3, 1948 FOREIGN PATENTS 111,108 Australia July 22, 1940 

